[TSan][Darwin] Fix CheckAndProtect() for MappingAppleAarch64

In the new TSan runtime refactoring this line was changed:
```
ProtectRange(MetaShadowEnd(), TraceMemBeg());
-->
ProtectRange(MetaShadowEnd(), HeapMemBeg());
```

But for `MappingAppleAarch64` the app heap comes before the shadow,
resulting in:
```
CHECK failed: tsan_platform_posix.cpp:83 "((beg)) <= ((end))" (0xe00000000, 0x200000000)
```

rdar://86521924

Differential Revision: https://reviews.llvm.org/D115834